Bellows folding machine



Julie I5, 19.5.4 A, McMlLLAN ETAL 2,680,998

BELLOWS FOLDING MACHINE Filed Jan. 24, 1950 6 Sheets-Sheet l Gtorllegs June l5, 1954 A. MCMILLAN ETAL BELLOWS FOLDING MACHINE Filed Jan. 24. 1950 III 6 Sheets-Sheet 2 Snvcntors Gtforncgs Jne'15, 1954 A. MCMILLAN ETAL 2,680,998

BELLOWS FOLDING MACHINE Filed Jan. 24, 1950 6 Sheets-Sheet 3 8 i y wwwrun@ June l5, 1954 A, MoMlLLAN ETAL 2,680,998

BELLOWS FOLDING MACHINE Filed Jan. 24, 1950 6 Sheets-Sheet 4 June 15, 1954 A. MCMILLAN ETAL 2,580,998

BELLows FOLDING MACHINE Filed Jan. 24, 195o 6 sheets-snee*b 5 rwentors Gttcarmzgsv Jime 15, 1954 A. MCMILLAN Ag1-AL 2,680,998

BELLOWS FOLDING MACHINE Filed Jan. 24, 1950 6 Sheets-Sheet 6 Patented June 15, 1954 BELLOWS FOLDING MACHINE Archie McMillan, Bernie Becker, and Arthur C.

Mickey, Saginaw,

Mich., assignors to General Motors Corporation,.Detroit, Mich., a corporation of Delaware Application January 24, 1950, Serial No. 140,302

20 Claims.

This invention relates to folding machinery and more particularly to a continuous bellows folding machine.

The bellows forming machine folds a continuous paper strip into a tube and then forms pleats in the tube. The paper or other suitable sheet ltering material is fed in a continuous strip into the machine between the internal and external tube formers. The internal tube former is a generally cylindrical member supported from the top by a bridge located at the entrance side of the machine. The external former is mounted concentrically around the internal former. The external former is shaped to provide a wide flat scoop-like portion disposed below the entrance end of the internal former, and a generally tapering intermediate section terminating in a cylindrical portion closely surrounding an intermediate portion of the internal former. Two groups of power driven rolls then engage the paper tube and draw it along the internal former. One of these rolls is heated to seal the joint in the paper tube. The terminal end of the internal former gradually tapers from a circular cross section to a square cross section and has a reduced portion connected to an extension having a small square section. The pleat folding portion of the machine surrounds this square extension. The pleat formers consist of four series of formers mounted on endless chains. Air

pressure is supplied through the internal tube former to apertures in the reduced or neck portion to hold the blank in contact with the pleat foi-mers. The top and bottom series of formers grip the flat top and bottom portions of the square blank over the neck part of the former to fold opposed pleats. The series of formers on each side grip the flat side portions over the neck portion of the former to fold opposed pleats intermediate the opposed top and bottom pleats. The formers then move both longitudinally and .radially to release the completed bellows while a mandrel extension holds the completed bellows centrally located between the formers.

A primary object of the invention is to provide a continuous folding machine employing air pressure to assist in the folding .of the sheet material in cooperation with mechanical folding devices simultaneously operating on the sheet material.

Another object of the invention is to provide in a continuous bellows folding machine an internal mandrel and external tube forming guide, areduced portion in said mandrel where the tube is supported by air pressure while the tube is 2 formed into a series of pleats as it is continuously passed through the machine.

Another object of the invention is to provide in "a continuous folding machine a mandrel having a reduced portion with air pressure connections to support 'the tube over the reduced portion and external members to fold the tube in cooperation with the internal air pressure.

Another object of the invention is to provide in a continuous folding machine a plurality of folding elements moving in a continuous path so that they engage the blank and form the folds and they move longitudinally with the blank as it moves through the machine and simultaneously withdraw from the folds.

These and other objects of the invention will be more fully explained in the following drawings and specification which provide a complete description of a preferred embodiment of the invention.

Figure 1 is a partial side view of the folding machine.

Figure 2 is a partial perspective view of the blank showing the successive steps of forming a bellows.

Figure 3 is a partialelevation view of the folding machine.

Figure 4 is a view on'the line 4-4 of Figure l.

Figure v5 is a view on 'the line 5-5 of Figure 4.

Figure 6 is a partial section on the line 6 6 of Figure 1.

Figure7 is a partial-section on the line 1 1 of Figure 1.

Figure 8 is a 'section on the line 3 8 of Figure l with parts broken away and in section.

Figure 9 is a side View of the pleat forming portion of the machine.

Figure 10 is a partial cross sectional view of the pleat former drive gearing von the line lll-i0 of Figure 11.

Figure 11 is a partial cross section of the pleat formers on the line Il-ll of Figures 1 and 9.

Figure I2 is a sectional view of the pleat formers vshowing the mandrel.

The folding machine is mounted on a table l0 which is supported by suitablelegs l 2 as shown in Figures 1 and 2. At the entrance end of the machine a pair of posts I6 and I'l are mounted at each side of the table I0 to `provide support for guiding and gluing mechanism. As the endless strip of sheet material enters the machine it engages the roller 4I8 which is supported by a pair of brackets 20 `which are shown in detail in Figure 5. The brackets 20 also 'provide support fora platen 22 andan upper guide 24 and side guides 26. The post I6 on the right looking toward the entrance of the machine as in section 4 supports a glue nozzle 28 by means of a crosshead 39. The crosshead 39 is slidably mounte on the vertical slidable head 32. A suitable tongue and groove connection 34 between the vertical slide 32 and the crosshead 39 allows horizontal sliding movement of the crosshead 30 relative to the sliding head 32 to transversely adjust the nozzle 22|. An adjusting screw 36 is rotatably mounted on and axially restrained by the bracket 38 secured to the crosshead 39 and threadably secured in a bore in the slide member 32. The slide member 32- is slidably mounted on a block 49 secured to the post I5 by a similar tongue and groove connection 42. Another adjusting screw 44 is rotatably mounted in a bracket 46 secured to the block 40 and threaded into a bore in the slide member 32 in order to vertically adjust the slide member. Immediately above the nozzle 28 a flexible platen extension 48 is attached to the upper guide 24 to support the paper at the point where the adhesive impinges on the paper.

The other nozzle 52 is located on the upper side of the paper and supported from the left post Il by a similar crosshead 30. As described above in conjunction with nozzle 28, the crosshead 39 is slidingly mounted by a tongue and groove connection 34 on a slide member 32. The slide member is similarly connected by a tongue and groove connection 42 to a supported block 49 which is attached to the left post I6. Similar adjusting screws 35 and 44 control the horizontal and vertical position of the nozzle. A platen extension 54 is supported by platen 22 immediately below the nozzle 52 in order to support the paper at the point where the adhesive impinges on the paper.

The upper guide 24 has an axial extension 55 extending above the paper to the entrance portion 58 of the external former E9. The entrance portion S on the external former is flat and is supported by posts '53 on table I0. The external former Si) extends forward and gradually changes from the iiat section at the entrance edge 58 as shown in Figure l to a substantially cylindrical shape with an opening at the top as shown in Figure 6. At this point the entrance edge of the internal cylindrical former or a man drel 92 is positioned within the external former. The mandrel S2 is supported by a hanger 94 depending from the bridge plate 65 supported between the bridge arches 'I2 and 14. The rear bridge arch 'I4 may be braced bya diagonal strut '|I3. A compressed air pressure supply passage 18 conducts air pressure to the hollow interior of mandrel 82. The external former 59 extends forward through the support or bridge arches 'i2 and 'i4 and gradually approaches a circle cross section and terminates at about the center of the mandrel E2 in a substantially cylindrical terminal portion 82 whichis spaced from the mandrel |32 a distance substantially equal to the thickness of the sheet material or paper being folded in the machine. The terminal portion S2 of the outer former 59 has a reinforcing ring 84 which is secured to the supported post 89. A folding guide 88 is adjustably mounted on the top portion of the reinforcing ring 34.

The paper tube then moves along the cylindrical mandrel 62 to a pair of semi-cylindrical guides 92 which completely surround the mandrel 62. The guides 92 are secured by means oi sup- Y ports 94 on an adjustable plate 96. Each of the .suitably journalled in adjustable plates 95 has a slot 93 which symmetrically diverges from the axis of the cylindrical mandrel 62. The plates Sii rest upon a base |99 which is suitably supported on table i9 by block |92. The plates 96 are adjustably mounted on the base |99 by the bolts |94 which extend through the diverging slots 98 and have suitable winged nuts clamping the plate 95 to the base |99. An additional folding finger |915 may also be suitably supported by a post |99 secured to one of the supports 94.

The paper tube then passes along the mandrel 62 to the driving and sealing mechanism which is mounted on a rectangular frame H2 having a channel-shaped cross section and suitably sup ported on -the table I9 by support blocks IMI. The frame is made in two parts in order to pro vide easy access to service and remove the mandrel. The lower part I I6 is pivoted by hinge I8 to the upper part |219. At the opposite side of the frame a locking bolt and hand wheel |22 are ivotally secured to the lower portion of the frame IIB and are swingable into the slot in the latch plate |24 which is secured to the upper portion |2 of the frame. The driving mechanism is driven by the pulley |29 which is mounted on the shaft |28 as best shown in Figure 3. The shaft |23 is suitably journalled in abearing |32 in the lower portion oi the frame and bearings |34 and |35 located beneath the mandrel S2 on each side of the center of the mandrel. A rubber drive wheel |38 is mounted on the shaft |23 between the bearings |34 and |33. The rubber wheel |38 is secured to the shaft by being clamped between suitable hub members Iii; which are secured to the shaft. A bevel gear |ri2 secured to the outboard end of shaft |28 beyond bearing |36 and meshes with a bevel gear |46, on the end of shaft |45 which is suitably journalled in bearings |48 and |52 secured to the upper portion |23 of the frame. A rubber wheel |54 is secured in the same manner as wheel |38 to the shaft |46 by a hub |56. A bevel gear |53 is secured on the outboard end of shaft |49 and meshes with bevel gear |52 on shaft |54. The shaft |64 is bearings It and |93 and supports a driving and heating wheel |72 which is suitably secured tov the shaft |64. The wheel |2 is made o metal and has an annular electric heating element |14 located adjacent to the perimeter of the wheel. The electricity is supplied to the heating element |14 by means of the wires |16 extending through a hollow portion ITB of the shaft |615. The electric current is transferred from a terminal box |32 mounted on the frame I2 by means of brushes |84 which engage a pair of commutator rings |855. A gear |89 is secured to the shaft |54 adjacent to bearing |58 and meshes with a gear |92 on shaft |94. yThe shaft |94 is suitably joined in bearings |96 and |98 which are supported on the upper portion 29 of the frame. Between the bearings I and |98 a rubber wheel 292 is mounted on the shaft by means of a suitable hub 294. It will be noted that the wheels |38 and |12 are located on the vvertical axis of the mandrel 32 and that the wheels |54 and 292 are mounted on the horizontal axis of the mandrel 62. Each of these wheels has a concave surface and contracts an idler roller 20E which has a transversely convex surface to conform with the exterior surface of the mandrel S2. The rollers 293 are mounted on a bearing 208 which is supported on a pin 2 I2 and mounted in suitable apertures in the bulkhead 2M, The bulkhead 2|4 has cavities for the rollers 2&6 and has sucient length to extendv beyond both ends of the apertures 21% in thev surface of the mandrel .532 through which the rollers 2%" Contact their adjacent driving Wheels. Thus the air pressure between the paper and the hol'- low mandrel will' not escape out of the apertures- ZIYE. The bulkhead 2id has a central aperture 2l8 connecting with passage 28. to allow the passage of air through the bulkhead.

After the paper tube passes through the driv ing and sealing rollers in frame H2V it enters another set of driving and sealing rollers in a frame 222. A frame 222 has a second set or" rollers 533, ist, H2 and 262 located and driven in the same manner as in frame H2'. The upper roller H2 may be the heating roller but is preferably a rubber driving roller such. as roller lSLl. The frame 222 has a driving shaft 828 extending thereof which has pulleys 224 and 22S secured thereto. rThe shaftsv Vit in each of these frames H2 and 2F52 are interconnected by a belt 228 which interconnects pulleys 22.4 and i255. The pulley 22e is driven by a belt 232 which extends downwardly to a suitable pulley on a driven shalt of gear box 232. The electric motor 234 suitably drives the gee r box through the belt 23E which is connected to the pulley 23B on the input shaft of the gear box. The driving wheels of frame 222 engage a second set of rollers 228 mounted in a second bulkhead 2id.

The forward end of the mandrel forward of the frame 222 gradually changes from a circular cross section to a square cross section having substantially the same perimeter. At this point the mandrel has a sharply tapered or reduced portion 2d@ which sharply reduces the size ol the mandrel to the square extended portion 2M which ts in the central aperture of the bellows forming on this machine. The tapered portion 240 of the mandrel has a plurality of apertures 2.44 cn each portion to allow air pressure to support the paper tube in this region.

The pleat forming mechanism is mounted about this reduced portion of the mandrel and is supported from an annular plate 245 supported in vertical position on a pair of legs 2HE secured to a sliding plate 252. The plate 252 is slidingly mounted on a table lil and retained in position by guides 254. The forward and rear position of the folding mechanism with respect to the mandrel 6E? is regulated by an adjusting mechanism best shown in Figures l and 3. An elongated stud. is secured to the central portion of the plate 252 and extends through apertures in the bifurcated portion of anchorage 256. A nut 258 is threaded on the stud 255 and located between the bifurceted portion of the anchorage 25@ so that the plate 2552 may be moved forwardly or rearwardly by rotating the nut 258. The pleat folding mechanism consists of four series of pleat formera. There is a top series 22S andl a bottoni series 2&2 positioned on the vertical axis of the mandrel above and below thecenter. One side series 25s is located on the right side of the mandrel and the other 256 is located on the left side of the mandrel as viewed in Figure 11. Each of these series of folding plates 269, 252, Z and 266 consists of a plurality of trapezoidally shaped formers 268 which are best shown at the top and bottom in Figure ll. As best shown in Figure l2, each of the formers 268 has an apertured pintlc portion 22u at the base and a pair of ears 222 extending at right angles therefromand having an apertured portion engaging the. outside of the pintle of the adjacent former 28'. Thus, as

the adjacent formers 258 are pinned together by pins 2M extending through the apertured ears and pintle portions, they form a chain which extends over sprockets 216 and 218. 'Ihe sprockets Elu and 2l@ are secured respectively to shafts 282 and 2te which are mounted in bearings supporting apertures in the bearing supporting arins 256.. These arms are located on each side of the pleat formers and extend generally rear'- wardly and toward the axis of the mandrel 62. The shaft 2214 is supported close tol the. axis of mandrel 62 so that the pleat forrners pass closely adjacent to the tapered portion of the mandrel to grip the paper and the shaft 232v is further removed' from the mandrel so that the pleat formers travel along the mandrel to shaft 284i and gradually recede from the mand-rel to completely release the pleats of the folded bellows. The arms 2st have an adjustable portion. 288- which supports the bearing shaft 284. Thusv the chain consisting ofA a series of formers 258 can be made taut by adjusting the position of support 268 foi1 shaft 22d. The adjustable portion 288v of support arms 288 is adjusted by a set screwI 290 and held in position by blockingl the screw 292. Each or" the shafts 224 has a bevel gear 2M at each end. The bevel gears 22e mesh withV each other so that all the shafts 2&3 are driven at the same speed. Similarly, a gear 29B is attached to each end of each of the shafts 222. The gears 295 on the ends of adjacent shafts 282- mesh with each other to drive the gear andthe shafts' at the saine speed.

rlhe pleat formers are driven by extending the shafts 252, its on the lower set of pleat formers 252. This shaft 232 extends outwardly through a bearing 2st mounted on the plate 252 by a support A sprocket 3&6 is secured to the shaft 282 on the outboard side of bearing 258. A. chain 33t running on the sprocket 34 and the output shaft of the variable speed gearbox 232 provides the power to drive the. pleat formers. The shaft 23e of the lower group ofy pleat formers 252 is also extended through. a bearing 3533 mounted on support 392. On the inward side of the bearings and 3% the shafts 232 and 28s are inter-connective by gearing best shown in Figure 19. This gearing consists of a spur gear M2 secured to the shaft 282 and a pinion 3M secured to the shaft 284. These gears are inter-connected to rotate in the same direction by the idler gear Si El which is mounted to mesh with both gear Si?. and pinion 3M by the stub shaft Sil on adjustable arm SH3.

The paper or sheet material used in this folding machine is supplied in strips or ribbon form rolled on suitable supply drums. The material is drawn by the machine from a suitable drum and enters the machine over the roller i8 and moves between the platen 22 and the guide` 2li. As the paper leaves the guide the nozzle 28 applies adhesive material to the underside of one edge of the sheet material and another nozzle 52- applies adhesive to the upper side at the other edge. The sheet material in flat forni as shown at 322 in Figure 2 then passes onto the entrance edge t8 of the externalv former 5i). The external former gradually tapers from the flat section at the entrance section e8 to a rounded section with a large opening at the top in the intermediate region. At this point a cylindrical internal-former or mandrel is positioned centrally Within the external former. This mandrel about which the tube is formed extends forwardly' in the machine.. The external former continuesl to confverge upon the mandrel so that at the outlet end of the external former it has a circular shape closely surrounding the cylindrical mandrel and forming the paper sheet material into a tube at 32d. The fingers 38 and Ict are positioned in Contact with the edges of the sheet material to assure the uniform overlapping of the sheet material preparatory to the nal sealing operation. Generally the first finger 88 presses the inner edge of the sheet material against the mandrel, while the second finger itt presses the top edge on the inner edge. The tube then passes through a guide portion 92 which holds the tube in a proper position around the mandrel for the driving and sealing of rollers mounted in frame H2. The rubber rollers or wheels 138, 154, and 202 contact the outside of the paper side is contacted by the idler rollers ZEE. The top roller or wheel 72 which contacts the paper over the conventional idler roller 295 has an electric heating element Vid to seal the adhesive or heat sealing resin to secure the joint in the tube. The tube then passes forwardly on the mandrel to a second and similar series of driving rollers. This second series of rollers is merely employed to minimize likelihood of a lcalized strain on the tube that might tear the tube while it is going through the machine. The tube then passes to the section of the mandrel which changes from a cylindrical cross section to a square cross section 32% in Figures 2 and l2. It will be noted that the surfaces of this square end of the mandrel are in alignment with the edges of the pleat rormers. The square tube then moves oil the square end of the mandrel and over the tapered portion Zitti of the mandrel. At this point air pressure entering through the hollow mandrel and apertures 2M maintains an outward pressure within the tube to hold it at its square form. Thus, when the top pleat former 26s and the bottom pleat former 252 engage the paper tube to form an inside crease between a pair of pleats, the air pressure maintains the pleat extending between the pleat formers. As the top and bottom pleats are moved forwardly by the top and bottom pleat formers, a right pleat former 25d and a left pleat former 256 simultaneously engage the tube and form an inward crease between a pair of side pleats. The air pressure maintains the paper extended between the pleat ormers to form the outwardly extending pleat. The process is then repeated when the top and bottom pleat formers form another pleat and the side pleat formers form another pleat so that the pleats are continuously formed as the paper tube continuously moves through the machine. It is preferred that the top and bottom pleat formers complete the formation of the top and bottom pleats before the next pair or side pleat formers engage the tube to form the next side pleats. Similarly, these side pleats are completed before the next top and bottom pleat formers engage the tube to form the next top and bottom pleats. The preceding pleat can be completed before the next pleat is started, due to the fact that the iormers 253 spread apart when they pass over the small diameter sprocket 2'l3. They should spread far enough apart so that there is no interference and the next adjacent former will not engage the paper before the prior former has completed its pleat. In one machine making a bellows about Il inches in diameter and employing formers about 11/2 inches deep, a small diameter three tooth sprocket which will spread while the inapart operates successfully. As 12, the shaft 282 is spaced further from the axis than the shaft 28A so that as the pleat formers move longitudinally along the mandrel they recede from the mandrel and are gradually withdrawn from between the pleats of the bellows. The bellows 328 are mounted in a central position between the pleat formers as they are withdrawn by the extension 242 of the mandrel. The machine makes a continuous a1- ternately pleated octagonal bellows which may be cut to any desired length.

The above described bellows forming machine is a preferred embodiment of the invention. It will be apparent that numerous variations of the invention may be made within the scope of the patented claims.

We claim:

1. In a folding machine, a mandrel, means to form a continuous strip into a tube around said mandrel, said mandrel having a reduced portion at the end, means to supply compressed air between the tube and the reduced portion of the mandrel, and means to form pleats in the tube engaging the outside ofthe tube over said reduced portion comprising an endless belt having a plurality of pleat formers mounted radially on said belt.

2. In a folding machine, a mandrel, means to form a continuous strip into 'a tube around said mandrel, said mandrel having a reduced portion at the end, means to supply compressed air between the tube and the reduced portion of the mandrel, a plurality of series of pleat formers, and each series of pleat formers being mounted on an endless belt to engage said tube over said reduced portion.

3. In a folding machine, means to guide a tube along its axis, said guide means having a rectangular terminal portion and an adjacent reduced portion, means to drive said tube on said guide means, means to supply air pressure at the reduced portion of said guide to internally support said tube, means to coniine said internal air pressure, an endless belt, pleat formers mounted on said belt, one end of said belt being mounted adjacent said tube so that the pleat formers engage said tube at the reduced portion of said guide, and the other end of said belt being mounted further away from the axis so that the pleat formers are automatically withdrawn from said pleats.

4. In a folding machine, means to guide a tube, means to internally support a tube, an endless belt positioned above and below said guide, an endless belt positioned on each side of said guide, formers on said belts, one end of each of said belts being positioned adjacent said guide to pleat said tube, and the other end of said belts being positioned away from said tube to withdraw said formers from said pleats.

5. In a folding machine, means to guide a tube having a reduced portion, means to internally support a tube, an endless belt positioned above and below said guide, an endless belt positioned on each side or" said guide, formers on said belts, one end of said belts being positioned adjacent said guide to carry the formers into said reduced portion to pleat said tube, and the other end of said belts being positioned away from said tube to withdraw said formers from said pleats.

6. In a folding machine, means to guide a tube, means to internally support a tube, an endless belt positioned above and below said guide, an endless belt positioned on each side of said guide the formers best shown in Figure formers on said belts, one end of each A,of said belts being positioned adjacent said ,guide to pleat said tube, and the other end of said belts being positioned away from said tube to withdraw said formers from said pleats, and means to -drive said belts so that the pleat formers positioned above and below the guide engage Vthe tube alternately with respect vto the side pleat lormers` 7. In a folding machine, a mandrel, means to form a continuous strip into a -tube around said mandrel, said mandrel having a portion of rectangular section with all sides having a Width substantially greater than .the .thickness of the continuous strip to substantially space internal opposed sides of the tube and a portion :of reduced section with all transverse `dimensions less than the same transverse dimension -of said rectangular portion, means to supply compressed air between the tube and said reduced portion of the mandrel, means to form lpleats yin the tube engaging the flat sides of said rectangular portion of the outside of the tube over said reduced portion, and means to disengage said pleat forming means from said tube.

8. In a folding machine, means to guide .a tube and angularly position adjacent sides of the tube, fluid pressure means to internally support -a tube, a iirst endless belt having a series of formers positioned to engage a rst vside of the tube to form pleats, and a second endless belt having a series of formers positioned `at a transverse angle .to said first endless belt to engage a second side of the tube located at an angle ,to the rst side to form pleats.

9. In a folding machine, a support, means having an axis mounted on said support to guide a tube for movement coaxially :along its axis, means mounted on said support `and engaging the tube to drive said tube coaxially in one direction on said guide means valong said axis, fluid means mounted on said support and located within the tube to confine fluid under pressure within a portion of said tube, means mounted on said support and connected to said fluid means to supply fluid under pressure to said coniining means to internally `support Asaid portion or" said tube, means forming pleats ,in said tube including an endless belt rotatably mounted on said support, pleat formers mounted on said belt, one end of said belt being mounted on said support adjacent said portion of .said ytube and said pleat formers engaging said portion of the tube to form pleats in cooperation with said uid means, the other end of said belt being mounted on said support further away from the axis and said pleat formers being automatically ymoved with the tube and withdrawn from said pleats.

l0. In a folding machine, a support, guide means having an axis mounted on said support to guide a tube for movement coaxiallyalong 'its axis, said guide means having a portion of rectangular section to rectangularly shape the tube and a folding station, means mounted on said support to drive said tube axially on said guide means from said portion of rectangular section to said folding station, iiuid means mounted on said support within said tube at said folding station to confine fluid under pressure within the tube portion of rectangular section to support said tube, means to supply uid under pressure to said uid means to internally support said tube portion of rectangular section, means forming pleats in said tube including a flrst endless belt mounted on said support and extending axially adjacent said guide means, a second l.endless belt mounted on .said-.support and extending axially ,adjacent said .guide means and located at a transverse angle to .said nrst end-less belt, pleat formers mounted on said belts, one end of said belts vbeing 4'mounted adda-cent said rtube opposite said fluid means .and ,said pleat formers engaging the air pressure supported portion vof said tube 'to form pleats cooperation `with .said fluid means, the 4other end -of fsa-id ebelt ybeing v4mounted further awa-y from the .axis .and said pleat formers being automatically moved with the tube and withdrawn from said pleats.

l1. Inarfoldi-ng machine, aguide having a folding station holding opposite -sides of a tube in spaced :relation about the tube axis at said fold-- ing stat-ion, a folding member transversely positioned adjacent .one side of said guide at the folding station, mechanism moving said folding member in a unidirectional cyclic path where the member during each cycle is vmoved substantiall;7 perpendicularly inwardly toward said axis and remaining spaced `from sai-d axis to perform a folding operation on .one side of the tube while said one side remains lin spaced relation to the other side of the ltube and then in parallel relation to the pleat move longitudinally and -outwardly to 'withdraw said folding members from the tube, means cooperating with said mechanism to linterna-ily support .said tube at the folding station, a-nd `to move the tube in one ydirection through the folding station to .present another tube portion vduring each cycle of movement of said mechanism.

l2. In a bellows folding machine, a support, guide means vhaving a ,folding station and mounted .on .said support to guide a :tube axially .and hold :opposite sides in `spaced relation, means mounted on said support and operatively engaging the tube to continuously move a sheet material tube axially along said `guide means, means mounted ion said Support to apply internal `fluid support to said tube at said folding station, and means mounted on said support andcontinuously moving with the sheet material tube axially along' said guide means and moving transversely inwardly vtoward said tube and having transverse lineal portions engaging .said tube to form transv erse pleats in Aone side of said .tube while said one .side remains in :spaced relation to the other side'of the tube at said folding station.

y1.3. In a folding machine, fluid support means to suppl-y and corinne internal air pressure yman axially extending portion of a tubular blank ,to internally support the `tubular blank, means yto form the internally supported portion of the blank linto ya tube of polygonal section having opposed sides transversely substantially spaced from eachother, means .to form transverse pleats including a .transverse Apleat former having a transversely extending lineal creasing means located at said fluidsupport means and vengaging one side `of lsaid internally supported polygonal section along a `transverse line `to vform transverse pleats in said one side while spaced from the other side, and means to move the tubular blank over said fluid support means and to move said pleat former cooperatively to support and pleat successive portions of the tubular blank.

14. In a folding machine, fluid support means to supply and confine internal air pressure in an axially extending portion of a tubular blank at a folding station to internally support the tubular blank, means to form the blank into a tube of rectangular section having opposed sides substantially spaced from each other by said iuid support means at said folding station, transverse pleat formers having transversely extending lineal creasing means at said folding station engaging one side of said rectangular section supported by said fluid support means along a transverse line to form transverse pleats in said one side, and means to move said pleat formers and means to move the blank over said iiuid support means into operative engagement with said transverse pleat formers to support and pleat successive portions of the tubular blank.

15. In a bellows folding machine, guide means having a folding station, said guide means having a portion with a polygonal section having all sides of substantial length to guide said tube of polygonal section to said folding station, means to apply internal fluid support to said tube at said folding station adjacent said polygonal -section of said guide means, means to continuously move a sheet material tube axially along said guide means over said portion of polygonal section to said folding station, and means positioned adjacent and movable to engage the adjacent ilat sides of the polygonal section of the tube at said folding station and forming pleats in adjacent angularly related sides of the tube.

16. In a folding machine, a mandrel having a longitudinal axis, means to form a continuous strip into a tube coaxially around said mandrel, said mandrel having a reduced portion at the end, all transverse dimensions of said reduced portion being less than the corresponding transverse dimension of said mandrel adjacent said reduced portion, means to supply compressed air between the tube and the reduced portion of the mandrel, and means to form pleats in the tube engaging the outside of the tube over said reduced portion.

17. In a folding machine, a guide having a first portion having a large -polygonal section, a second portion having -a tapered reducing portion and a third portion having a small polygon section extending axially of said guide, means to move a tube fitting said large portion of the guide axially along said guide from the first portion to the third portion, transverse formers having ar transversely extending creasing member to fold transverse pleats in the tube at the reducing portion to reduce the internal diameter of said tube to fit the small extension, means to supply cornpressed air to the reducing portion to hold the tube in contact with the folding means, and said large portion and said small extension of said guide means confining said air within the portion of said tube over said reducing portion.

18. In a folding machine, a guide having an axis to guide a tube axially and hold opposite sides in spaced relation at a folding station, means to supply and confine compressed air in a tube at said folding station to hold the opposed sides of the tube in spaced relation, a plurality of folding members completely surrounding said tube at said folding station, each of said plurality of folding members having a lineal creasing mem-v ber extending transversely of the axis of said guide means to engage the tube, means to continuously move the tube on said guide past said folding station, and means to move said folding members longitudinally of and inwardly toward said axis to engage all sides of the tube with said members of said folding means to form a. series of transverse pleats in each side of said tube as the tube moves past said folding station.

19. In a folding machine, a guide having a folding station to guide a tube axially through the folding station, drive means to move the tube in one direction through the folding station with the internal sides of the tube substantialhT spaced from each oth-er, folding means at said folding station cooperatively engaging opposite surfaces of the same tube wall portion to form pleats including mechanism at the folding station moving in one direction in -a cycle to engage, fold and with-draw from one surface of the tube, fluid means at the folding station movably supporting the opposite surface of the tube wall portion to coact with said mechanism to form pleats, and

' said drive means moving the tube through the folding station to place successive portions of said tube at said folding station between said mechanism and fluid means so that a series of individual pleats are formed in said tube.

20. In a folding machine, a guide having a folding station to guide aitube axially through the folding station, drive means to move the tube in one direction through th-e folding station with the internal sides of the tube substantially spaced from each other, folding means at said folding station cooperatively engaging opposite surfaces of the same tube wall portion to form pleats including mechanism at the folding station moving in one direction in a cycle .to engage, fold and then in parallel relation to the pleat simultaneously move with the tube and withdraw from one surface of the tube, means at the folding station movably supporting the opposite surf-ace of the tube wall portion to coact with said mechanism to form pleats, and said drive means moving the tube through the folding station to place successive portions of said tube at said folding station between said mechanism and means so that a series of individual pleats are formed in said tube.

References Cited in the le of this patent UNITED STATES PAIENTS Number Name Date 465,211 Schenck Dec. l5, 1891 842,823 White Jan. 29, 1907 898,167 Avery Sept. 8, 1908 969,555 Neal Sept. 6, 1910 1,290,800 Teall Jan. 7, 1919 2,014,649 Ginn Sept. 17, 1.935 2,033,717 Kopetz Mar. 10, 1936 2,123,175 Balsam July 12, 1938 2,169,205 Hornung Aug. 8, 1939 

